Objective: The quantification of basophil activation by flow cytometry is a useful tool for the assessment of immediate-type
responses to food allergens and the prediction of clinical tolerance in food allergy patients. The aim of this study is to
investigate how the analysis of allergen-induced CD63 up-regulation by flow cytometry can be effective in monitoring the
acquisition of clinical tolerance by specific oral desensitization in food allergy. To our knowledge, this is the first study to
examine this topic.
Materials and methods: Three male patients affected by cow’s milk allergy underwent successful oral desensitization to
cow’s milk. In order to monitor the acquired clinical tolerance that occurred after treatment, we performed laboratory tests
for total and specific IgE, specific IgG4 and the Basophil Activation Test (BAT) both at baseline and at the end of the
Results: Using a fluorescent enzyme immunoassay, the comparison of specific cow’s milk antibodies before and after
treatment showed a decrease of specific IgE levels, without reaching normal values, and an increase of specific IgG4
levels. A complete suppression of cow’s milk proteins (a-lactoalbumin, b-lactoglobulin and casein) induced CD63 regulation
was observed in all three reported cases.
Conclusions: Using flow cytometry, food allergen-specific basophil responses could be monitored in order to identify an
acquired tolerance induced by desensitization treatment. Although further studies are needed to develop this important new
topic, it was interesting to note that the BAT seemed to be more sensitive and characterized by a close correlation with